A $16 million lottery jackpot in Iowa may be forfeited if the mystery winner fails to explain by Friday how he got the ticket.

The winning ticket in the December 2010 Hot Lotto drawing was purchased in a Des Moines convenience store, but nearly a year later a winner from New York came forward with a vague story, confusing lottery officials.

On Dec. 29, 2011, just two hours before the deadline for a winner to claim the jackpot, two Des Moines attorneys presented the winning ticket to the Iowa lottery office, saying it had arrived by Federal Express earlier that day. The ticket had come from a P.O. Box in Bedford, N.Y., and was signed by a man named Crawford Shaw, who represented the Hexham Investments Trust.

Lottery officials, however, couldn't understand how the Hexham Trust or Crawford Shaw got the ticket.

Additionally, Shaw wrote the name of the trust incorrectly on the ticket, spelling it "Hexam" instead of "Hexham." No contact information for Hexham Investments Trust could be located for this story, and a search for the company turned up no results. A company called "Hexam Capital" is located in Scotland and is an investment group geared toward investors in the United Kingdom.

"This was a really unusual situation. We've never seen it before. We were asking the attorneys what took so long and where has this ticket been, and they didn't know," said Mary Neubauer, spokeswoman for the Iowa Lottery.

Attorneys representing Crawford Shaw did not immediately return calls for comment. Shaw could not be reached for comment.

"Normally, when a winning ticket comes in, we find out who purchased it, and where the ticket has been, and we find all that out before announcing the winner," Neubaeur said.

She said the lottery has security procedures and rules to ensure that the ticket wasn't sold illegally after purchase or bought by someone prohibited from playing the Iowa Lottery, including lottery employees.

Since that day, she said, lottery officials have been asking the attorneys to explain two things: who purchased the ticket, and where the ticket went after initial purchase.

"There is security camera footage showing what's occurring in the store when ticket was purchased. So we want to follow the trail of possession from that individual to the folks who turned it in here a year later so we can ensure that there's been nothing amiss with the purchase and presentation of the ticket," Neubaeur said.

Numerous people have alleged that the ticket was stolen from them, claims which have to be discredited, in part, by the real winner's story, she explained.

"In order to address those claims we need to have basic information, and it hasn't been given to us. We keep asking, 'Why don't you have that information?' and the questions simply haven't been answered," she said.

Neubeauer noted that the man who signed the ticket, Crawford Shaw, is involved in criminal and bankruptcy proceedings in New York and Delaware, a fact which she said could turn out to be irrelevant, but needs to be looked into.

"We have never seen a situation like this in the 26 year history of our lottery. Usually the process of claiming a prize is pretty quick and pretty easy," she said.

If no one comes forward to satisfactorily explain the situation by Friday's 3 p.m. deadline, rules dictate that the lottery will be forfeited. Neubaeur acknowledged that legal claims to the prize could be a possibility, but said that the lottery rules are clear on the security measures necessary to award the prize.

Lottery officials have also been keeping the Iowa Division of Criminal Investigations and the Attorney General's office informed of their investigation into the winner's claim, she said.

"We want there to be a happy ending to this story, but it's just an incredibly strange story," she said.